Estimate Your Recycled Concrete Order Without Hiding the Assumptions

Use the calculator in five stages:

1. Describe the area. Choose a rectangle, circle, known total area, or multiple-area layout.
2. Enter the layer depth. Record whether that is the intended finished depth or a loose placement depth.
3. Select a density. Use a low, middle, or high planning scenario, or select the custom option and enter the supplier’s product-specific figure.
4. Add adjustments separately. Compaction, waste or measurement variation, and supplier rounding are not the same thing.
5. Review the audit trail. The result shows net volume, base weight, each adjustment, the rounded order quantity, and optional truckloads and cost.

The calculator reports volume in cubic feet, cubic yards, and cubic metres. It reports weight in pounds, US short tons, and metric tonnes. Every result is a planning estimate, not a guaranteed purchasing or engineering quantity. The exact grade, density, material condition, and ordering method can change the amount that should be purchased.

The depth-basis question is important. A desired finished layer and a loose layer before consolidation are not necessarily equivalent, but the available evidence does not establish one conversion that works for every recycled concrete aggregate. The calculator therefore records the selected basis without silently changing it.

For an irregular driveway, path, or parking area, divide the layout into sections. Multiple-area mode supports rectangles, circles, triangles, and trapezoids, then adds their areas before applying one common depth. If different sections need different depths, calculate those sections separately and combine the resulting volumes or weights.

Measure the project area correctly

For a rectangle or square, measure the length and width at the relevant project boundaries. Include parking bays, turnouts, aprons, widened ends, and narrow connections that will receive material.

The area calculation is:

Area = length × width

Use the planned material depth rather than the excavation depth unless those figures are genuinely the same. Where excavation depth varies, one measurement taken at the shallowest or deepest location can misrepresent the total volume.

For a circle:

Area = π × radius²

The radius runs from the centre to the edge. If you measured all the way across, you measured the diameter. Divide it by two before entering the radius. Because radius is squared, entering the diameter as the radius produces four times the correct circular area.

Use known-area mode if the project’s square footage or square metres have already been calculated from a plan, survey, paving schedule, or separate takeoff.

Dividing an irregular layout

Most irregular layouts can be approximated with familiar shapes:

• Rectangle: length × width
• Circle: π × radius²
• Triangle: base × perpendicular height ÷ 2
• Trapezoid: sum of the parallel sides × perpendicular height ÷ 2

Draw a rough plan, label each section, calculate its area, and add the sections. Subtract islands or exclusions if they are large enough to affect the order materially.

A driveway might consist of a long rectangle, a wider rectangular parking pad, and a circular or semicircular turning area. Calculating those components separately is usually more representative than treating the entire project as one oversized bounding rectangle.

A sloping or uneven site is harder to describe with one depth. Use one depth only if it is a reasonable average across the area. If the grade changes substantially, divide the project into sections and calculate each section at an appropriate depth.

Common measurement errors include:

• mixing feet and inches without conversion;
• entering a circle’s diameter as its radius;
• omitting widened sections or narrow extensions;
• assuming excavation depth is uniform;
• applying one depth to sections that need different layers; and
• rounding each measurement before completing the calculation.

Record the original dimensions, units, depth basis, and a simple site sketch before changing the site. That record makes it easier to compare the estimate with a supplier’s quote and investigate any difference.

The formulas behind cubic feet, cubic yards, and tons

For a rectangular project measured in feet:

Cubic feet =
length in feet × width in feet × depth in feet

When depth is measured in inches:

Depth in feet = depth in inches ÷ 12

The direct formula for cubic yards is:

Cubic yards =
length in feet × width in feet × depth in inches ÷ 12 ÷ 27

Dividing by 12 converts inches to feet. Dividing cubic feet by 27 converts the result to cubic yards because one cubic yard contains 27 cubic feet. These are the same dimensional steps described by an aggregate producer’s calculation guide (see the cubic-yard method).

Volume alone does not establish weight. Apply a bulk density that is appropriate to the actual material:

Pounds =
cubic feet × density in pounds per cubic foot

If density is supplied in pounds per cubic yard:

Pounds =
cubic yards × density in pounds per cubic yard

For density in US short tons per cubic yard:

US short tons =
cubic yards × US short tons per cubic yard

Convert pounds to US short tons as follows:

US short tons = pounds ÷ 2,000

A US short ton and a metric tonne are different units, so the calculator labels them separately rather than presenting every result simply as “tons.”

For metric dimensions:

Cubic metres =
length in metres × width in metres × depth in metres

If the supplier states density in metric tonnes per cubic metre:

Metric tonnes =
cubic metres × density in metric tonnes per cubic metre

The principle is the same in either system: calculate volume first, then multiply by a compatible density.

Calculations should retain full precision internally. If the displayed volume is 4.44 cubic yards, the weight should still be calculated from the unrounded volume. Otherwise, the displayed volume and weight can appear to disagree because one result was derived from an already rounded number.

Keep the measurement type attached to every result:

• square feet and square metres measure area;
• cubic feet, cubic yards, and cubic metres measure volume;
• pounds, US short tons, and metric tonnes measure weight or mass.

“Cubic tons” is not a dimensionally correct label because it combines a volume description with a weight unit.

Choose a density instead of assuming every product weighs the same

Crushed concrete does not have one universal bulk density. Any conversion from cubic yards to tons assumes a particular product in a particular condition.

A commercial supplier calculator uses 2,410 lb/yd³, approximately 1.21 US short tons per cubic yard, for a named 1½-inch-minus crushed-concrete road-base product. That is a product-specific calculator assumption, not a rule for every recycled concrete aggregate (view the named product and density).

A third-party RCA calculator publishes a typical loose-density range of 95–115 lb/ft³, equivalent to approximately 1.28–1.55 US short tons per cubic yard. Its profiles use 95, 105, and 115 lb/ft³ while noting that moisture, pulverization, and the original concrete can affect density (review the published RCA profiles).

Another commercial supplier estimates crushed concrete at approximately 1.4–1.5 US short tons per cubic yard. The difference between that range and a 1.21-ton assumption is large enough to alter an order materially (compare the supplier estimate).

The calculator therefore offers these planning scenarios:

The 105 lb/ft³ setting is a calculation scenario, not a verified universal default. If the local supplier provides a density for the exact product, select the custom option and use that figure with its stated unit.

Bulk density may be affected by:

• particle-size distribution and fines;
• screened grade;
• moisture condition;
• how thoroughly the concrete was pulverized;
• residual mortar and the original concrete;
• contamination or mixed material;
• loading condition; and
• consolidation during handling and placement.

Product names also matter. Road base, Type 2, 21AA, screened RCA, and other local descriptions can refer to different gradations or specifications. Use the density for the product actually being quoted rather than choosing a figure merely because the material contains recycled concrete.

Confirm the unit before entering a supplier’s figure. These units are not interchangeable:

• lb/ft³;
• lb/yd³;
• US short tons/yd³; and
• metric tonnes/m³.

For example, a commercial calculator assigns 1.50 metric tonnes/m³ to a named Type 2 crushed-concrete product. That is not the same as 1.50 US short tons per cubic yard and must be entered under the appropriate metric unit (see the product-specific metric density).

Do not automatically reuse a crushed-concrete density for virgin crushed stone, crushed asphalt, or a brick-and-concrete blend. Those are different materials and may be sold under different grading, density, and ordering assumptions.

Separate net quantity, compaction, waste, and ordering increments

Begin with the unadjusted geometric result. This is the volume defined by the measured area and chosen depth before adding anything for placement, losses, uncertainty, or supplier rules.

For one percentage adjustment:

Adjusted quantity =
net quantity × (1 + percentage ÷ 100)

If the net requirement is 6.30 US short tons and the selected adjustment is 12%:

6.30 × 1.12 = 7.056 US short tons

The calculator keeps three concepts separate:

1. Compaction allowance represents a user-selected allowance associated with placing and consolidating loose material.
2. Waste or measurement allowance covers irregular boundaries, handling losses, uncertain measurements, and estimating variation.
3. Supplier order increment rounds the adjusted result to a purchasable quantity.

Published commercial suggestions vary. One guide recommends a 5–10% buffer (see the commercial ordering guidance). A published RCA worked example uses 12%, while supplier calculators for named recycled-concrete products display 15% for compression. These examples do not establish one universally correct percentage for every product or site (view a supplier calculator using 15%).

Compaction and waste are not synonyms. A site can have accurately measured straight boundaries and little handling loss while still using a placement allowance. Conversely, an irregular site can create measurement uncertainty even if the entered depth already represents loose material.

When both percentage fields are used, the calculator applies them sequentially:

After compaction =
net quantity × (1 + compaction percentage ÷ 100)

After waste =
after-compaction quantity ×
(1 + waste percentage ÷ 100)

Two sequential 10% adjustments produce a combined increase of 21%:

1.10 × 1.10 = 1.21

If the supplier combines all allowances into one percentage, enter that figure in one field and leave the other at zero.

A percentage allowance does not guarantee an exact conversion from desired compacted depth to loose delivered volume. The relationship can vary with gradation, moisture, placement method, equipment, subgrade, and performance requirements. Ask whether the supplier’s coverage or tons-per-yard figure describes loose, delivered, or compacted material.

Additional quantity may be needed where the site has:

• soft or pumping subgrade;
• substantial low spots;
• uneven excavation;
• uncertain grading elevations;
• material migration into the subgrade;
• settlement; or
• limited measurement access.

Apply supplier rounding last. If the adjusted estimate is 7.06 tons and the supplier sells in 0.25-ton increments, the commercial order rounds up to 7.25 tons. Keeping this step separate prevents supplier packaging or sales rules from appearing to be part of the geometric requirement.

Worked example: a 20-by-12-foot area at 6 inches

Consider a rectangular area measuring 20 feet by 12 feet with a planned depth of 6 inches.

1. Calculate the area

20 ft × 12 ft = 240 ft²

2. Convert depth to feet

6 in ÷ 12 = 0.5 ft

3. Calculate net cubic feet

240 ft² × 0.5 ft = 120 ft³

4. Convert cubic feet to cubic yards

120 ft³ ÷ 27 = 4.444... yd³

Displayed to two decimal places:

4.44 yd³

5. Apply the illustrative density

At 105 lb/ft³:

120 ft³ × 105 lb/ft³ = 12,600 lb

Convert pounds to US short tons:

12,600 lb ÷ 2,000 = 6.30 US short tons

6. Add the illustrative allowance

With a user-selected combined allowance of 12%:

6.30 × 1.12 = 7.056 US short tons

Rounded for display:

7.06 US short tons before supplier rounding

These dimensions, the 105 lb/ft³ density, and the 12% allowance reproduce a published RCA calculator example. The density and allowance are example inputs, not requirements (review the published worked example).

Density sensitivity

The geometric volume remains 120 ft³, but the calculated weight changes with density:

The difference between the low and high scenarios is 1.20 US short tons before allowances or supplier rounding. This is why an editable density is more useful than a hidden tons-per-yard conversion.

Optional hypothetical cost

The source example treats the displayed 7.06 tons as the cost basis and applies $12 per ton plus a $75 delivery charge:

Material: 7.06 × $12 = $84.72
Delivery:                  $75.00
Total:                    $159.72

Those figures reproduce the source’s arithmetic and are not current market prices. The example excludes taxes, labor, equipment, excavation, grading, drainage, and site preparation.

The interactive calculator follows a different, explicit precision policy: unless a supplier increment is entered, it calculates cost from the unrounded quantity. Using the exact 7.056-ton result would produce $84.672 in material cost and $159.672 before currency rounding, or $159.67 when rounded to cents.

Weight is likewise calculated from the full 120 ft³, not from the displayed 4.44 yd³. Retaining full precision avoids unexplained discrepancies between displayed volume, weight, and cost.

Coverage and general depth planning

Coverage reverses the normal quantity calculation. Instead of starting with area, begin with the available weight and selected density:

Volume = available weight ÷ density

Then divide the resulting volume by layer depth:

Area = volume ÷ depth

When using US units, convert available short tons to pounds before dividing by a density stated in lb/ft³. The result is cubic feet. Divide that volume by depth in feet to obtain square feet.

Coverage per cubic yard at a stated depth is geometric and does not depend on density:

The published coverage figures of 162 ft² at 2 inches, 108 ft² at 3 inches, and 81 ft² at 4 inches follow directly from one cubic yard containing 27 cubic feet (compare the published coverage table).

For example, at 4 inches—or one-third of a foot:

27 ft³ ÷ 0.333... ft = 81 ft²

Coverage per ton is different because weight must first be converted to volume using the selected density. A lower density produces more theoretical volume and coverage per ton.

These are uniform geometric coverage figures. They do not account for uneven subgrade, rut filling, edge losses, consolidation, or supplier rounding.

Choosing a planning depth

Commercial guidance is not fully consistent. One supplier describes 3–6 inches as common for many crushed-concrete projects, 4–6 inches for residential driveways, and 6–8 inches where heavier vehicles are expected. Treat those figures as supplier planning guidance rather than universal design requirements (compare the supplier’s depth ranges).

Another commercial guide gives generalized examples of 4 inches for driveways, 3 inches for patios, and 2 inches for walkways. Those examples illustrate how coverage changes with depth; they do not establish the correct design for every site.

Actual depth should reflect:

• subgrade soil and strength;
• drainage and susceptibility to saturation;
• slope and erosion exposure;
• expected vehicle type, loading, and frequency;
• whether RCA forms one layer in a multilayer assembly;
• required finished elevation;
• edge restraint;
• local specifications; and
• the supplied material’s grade and permitted use.

A light path and a parking area for heavy vehicles should not inherit the same depth merely because both use crushed concrete. For structural work, authority-controlled work, heavy loading, or a project requiring controlled gradation, obtain confirmation from the supplier and the relevant qualified professional.

Turn the estimate into a supplier-ready order

Before requesting a quote, write down the complete audit trail:

• net area;
• chosen depth;
• whether the depth represents finished or loose placement depth;
• net cubic feet, cubic yards, or cubic metres;
• selected density and unit;
• base pounds, US short tons, or metric tonnes;
• compaction allowance;
• waste or measurement allowance;
• quantity before supplier rounding;
• supplier order increment; and
• final estimated order quantity.

Then confirm the commercial and material details.

Product checklist

Ask the supplier:

• What is the exact product name and grade?
• What is its particle-size range and gradation?
• Is it screened recycled concrete only, or does it contain brick, asphalt, soil, or another material?
• What bulk density should be used for estimating?
• Which units and material condition apply to that density?
• Does the quote represent loose volume, scale weight, or a nominal tons-per-yard conversion?
• Is the product suitable for the proposed use?
• Does the project require controlled gradation, testing, structural approval, or authority acceptance?
• Is the required quantity currently available?

A generic “crushed concrete” description does not establish that a product meets a particular road-base, drainage, structural, or authority specification. Verify any controlled requirement before treating recycled concrete aggregate as an acceptable substitute.

Ordering checklist

Confirm whether the supplier sells by:

• scale weight;
• loose cubic yard or cubic metre;
• nominal tons per cubic yard;
• metric tonne or US short ton;
• bulk bag;
• minimum order; or
• whole truckload.

Also ask about minimum quantity, rounding increment, lead time, cancellation terms, and whether unused material can be returned. One supplier’s minimum or increment should not be assumed to apply elsewhere.

If truck capacity is entered, the calculator uses:

Estimated truckloads =
order quantity ÷ entered truck capacity,
rounded up to the next whole load

For example:

18 tons ÷ 10 tons per truck = 1.8
Estimated truckloads = 2

The entered capacity is only a planning input. Supplier fleets and available load sizes vary substantially; one aggregate supplier, for example, advertises deliveries ranging from 1 ton to 30 tonnes per load rather than one universal vehicle capacity (see the supplier’s stated load range).

Delivery-access checklist

Ask the delivering supplier to confirm:

• required gate and driveway width;
• turning and reversing space;
• required clearance from branches, wires, eaves, and other obstructions;
• whether the slope and surface can accommodate the proposed vehicle;
• how soft ground or buried services affect access;
• the intended unloading location;
• whether the vehicle can enter and leave that location;
• whether tipping is possible there; and
• whether someone must be present.

Do not adopt another supplier’s published vehicle dimensions or access rules as universal requirements. Give the delivering company an accurate description of the route and unloading point, then ask what vehicle it plans to send and what clearance it requires.

Cost checklist

A transparent estimate separates the components:

Material cost =
rounded or unrounded order quantity,
under the stated calculation policy,
× entered unit price

Total =
material cost + delivery + taxes + entered fees

Unless separately entered, the result does not include:

• labor;
• equipment rental;
• excavation;
• disposal;
• grading;
• drainage;
• geotextile;
• edge restraints;
• compaction equipment;
• permits; or
• site preparation.

Compare the calculator result with the supplier’s estimate. If they differ, ask which density, material condition, depth basis, allowance, sales unit, and rounding method the supplier used. A different result may reflect a more appropriate local product assumption rather than a mathematical error.

Mortar Desk publishes general building-material reference information. It is not a contractor or engineering adviser, and its reference role and limitations should be considered when using this planning tool. Product approval, structural decisions, specification compliance, site access, and delivery arrangements belong with the relevant supplier, authority, contractor, or qualified professional.

Frequently asked questions

How do I calculate tons of crushed concrete from length, width, and depth?

For a rectangular area measured in feet with depth in inches:

Cubic feet =
length in feet × width in feet × depth in inches ÷ 12

Pounds =
cubic feet × density in lb/ft³

US short tons =
pounds ÷ 2,000

Alternatively:

Cubic yards =
length × width × depth in inches ÷ 12 ÷ 27

US short tons =
cubic yards × density in US short tons/yd³

Use the density for the exact product where possible. Keep full precision until results are displayed, then apply any selected allowances and supplier ordering increment separately.

How much does one cubic yard of crushed concrete weigh?

There is no universal weight. Published commercial assumptions include 2,410 lb/yd³, approximately 1.21 US short tons/yd³, for particular recycled-concrete products. A separate 95–115 lb/ft³ scenario range converts to approximately 2,565–3,105 lb/yd³, or 1.28–1.55 US short tons/yd³ (compare the 2,410 lb/yd³ supplier assumption).

Use the local supplier’s figure for the exact grade. Confirm whether “ton” means a US short ton or metric tonne and whether the density describes loose, delivered, or another stated material condition.

Should I add 10% or 15% for compaction and waste?

Neither percentage is universally correct. Published commercial examples range from 5–10% buffers to 12% worked allowances and 15% compression additions.

Separate the reasons for extra material. Compaction concerns the user’s placement assumption. Waste or measurement allowance addresses losses, irregular boundaries, and uncertainty. Supplier rounding is a separate commercial step. Enter only allowances that match the project and ask the supplier how its estimate treats loose and compacted quantities.

How deep should crushed concrete be for a driveway?

Commercial guidance commonly mentions approximately 4–6 inches for residential driveways, with greater depths sometimes suggested for heavier vehicles. Other generalized guidance uses 4 inches as a simple driveway example.

These are planning references, not specifications. Subgrade strength, drainage, slope, traffic, layer arrangement, product gradation, finished elevation, and local requirements should determine the depth. Seek qualified guidance where the driveway carries heavy loads or forms part of specification-controlled work.

Why is my supplier’s tonnage different from the calculator result?

The supplier may be using a different:

• product density;
• moisture or loading condition;
• grade or gradation;
• loose-versus-finished depth interpretation;
• compaction or waste allowance;
• tons-per-yard conversion;
• minimum order;
• truck capacity; or
• rounding increment.

Compare assumptions rather than only final tonnage. Take the supplier your dimensions, net volume, selected density, base weight, allowances, and unrounded order estimate. Supplier calculators themselves caution that project conditions, material type, and compaction can change actual quantities and recommend confirming the estimate before ordering (see the supplier’s estimating disclaimer).

The useful result is the auditable result: net volume, selected density, base weight, each optional adjustment, and final order estimate. Accurate dimensions begin the calculation, but the local product’s density, grade, material condition, ordering increment, and delivery constraints determine what should actually be purchased.